Usually you can't. But here everything is just yose.
If white play a), LZ think white will win with near certainty (<5% winrate)
If white play b), LZ think both players are nearly equals and basically a tossup.
The only difference between both options is something like 5 points :
- Click Here To Show Diagram Code
[go]$$W White play a
$$ ---------------------------------------
$$ | . . . . . O X . . . . . . . . . . . . |
$$ | . . . X X X . X O . O X . . . . O . . |
$$ | . . X X O O X X O O X X . . . X O . . |
$$ | . X . O . . O O O , . . . X . X . O . |
$$ | . X O . . O . X X X . X . . . . X O . |
$$ | . . X O . . . . . . X O . X . . X O . |
$$ | X . X O . . . O . O O . O . . X O O . |
$$ | . X O . . . . . . . . . . O . X O O X |
$$ | O X O . . O . . . O . . . . . X O X . |
$$ | . O O X . X O O . , . . O O . X X . . |
$$ | . . . . . X X O . X . X X X . . . X . |
$$ | . . O O . . . X X . . . . . . . . . . |
$$ | . O X O . O X . . . . . . . . . . X . |
$$ | . O X X O . . . . . . . X X . X X O . |
$$ | . O X . . . . O . O . . . O . . O . O |
$$ | . 1 X 2 O O O X O , . X X . . O . O . |
$$ | 5 X O X X X X X X O . O O O . . . . . |
$$ | 3 X O 4 . . . . X O . . . . . . . . . |
$$ | . . 6 . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
- Click Here To Show Diagram Code
[go]$$W White play b
$$ ---------------------------------------
$$ | . . . . . O X . . . . . . . . . . . . |
$$ | . . . X X X . X O . O X . . . . O . . |
$$ | . . X X O O X X O O X X . . . X O . . |
$$ | . X . O . . O O O , . . . X . X . O . |
$$ | . X O . . O . X X X . X . . . . X O . |
$$ | . . X O . . . . . . X O . X . . X O . |
$$ | X . X O . . . O . O O . O . . X O O . |
$$ | . X O . . . . . . . . . . O . X O O X |
$$ | O X O . . O . . . O . . . . . X O X . |
$$ | . O O X . X O O . , . . O O . X X . . |
$$ | . . . . . X X O . X . X X X . . . X . |
$$ | . . O O . . . X X . . . . . . . . . . |
$$ | . O X O . O X . . . . . . . . . . X . |
$$ | . O X X O . . . . . . . X X . X X O . |
$$ | M O X . . . . O . O . . . O . . O . O |
$$ | M 2 X 1 O O O X O , . X X . . O . O . |
$$ | . X O X X X X X X O . O O O . . . . . |
$$ | . X O . . . . . X O . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
If I'm unconditionnally losing, but with 5 more points we're even, that means that I'm 5 points behind. I repeat, this is pure yose, so the remaining plays are mostly independant and there is no strategic consideration.
After that, the winrate swing were huge by just playing suboptimal yose